Lazy tile splitting

[grits] / src / gis-opengl.c

diff --git a/src/gis-opengl.c b/src/gis-opengl.c
index bb2095113d9830d2bc1ad874396b62a946136dea..4803168819d5e7c1c7b9407ebb97bf2cf01249fa 100644 (file)
--- a/src/gis-opengl.c
+++ b/src/gis-opengl.c
@@ -122,12 +122,10 @@ static void _set_visuals(GisOpenGL *opengl)
 /********************
  * Object handleing *
  ********************/
 /********************
  * Object handleing *
  ********************/

-static void _draw_tile(GisOpenGL *opengl, GisTile *tile)
+static void _draw_tile(GisOpenGL *opengl, GisTile *tile, GList *triangles)

 {
        if (!tile || !tile->data)
                return;
 {
        if (!tile || !tile->data)
                return;

-       GList *triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
-                       tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);

        if (!triangles)
                g_warning("GisOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f",
                        tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
        if (!triangles)
                g_warning("GisOpenGL: _draw_tiles - No triangles to draw: edges=%f,%f,%f,%f",
                        tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);


@@ -191,18 +189,41 @@ static void _draw_tile(GisOpenGL *opengl, GisTile *tile)
 static void _draw_tiles(GisOpenGL *opengl, GisTile *tile)
 {
        /* Only draw children if possible */
 static void _draw_tiles(GisOpenGL *opengl, GisTile *tile)
 {
        /* Only draw children if possible */

-       gboolean has_children = TRUE;
+       gboolean has_children = FALSE;

        GisTile *child;
        gis_tile_foreach(tile, child)
        GisTile *child;
        gis_tile_foreach(tile, child)

-               if (!child || !child->data)
-                       has_children = FALSE;
-       if (has_children)
-               /* Only draw children */
-               gis_tile_foreach(tile, child)
-                       _draw_tiles(opengl, child);
-       else
-               /* No children, draw this tile */
-               _draw_tile(opengl, tile);
+               if (child && child->data)
+                       has_children = TRUE;
+
+       GList *triangles = NULL;
+       if (has_children) {
+               /* TODO: simplify this */
+               const gdouble rows = G_N_ELEMENTS(tile->children);
+               const gdouble cols = G_N_ELEMENTS(tile->children[0]);
+               const gdouble lat_dist = tile->edge.n - tile->edge.s;
+               const gdouble lon_dist = tile->edge.e - tile->edge.w;
+               const gdouble lat_step = lat_dist / rows;
+               const gdouble lon_step = lon_dist / cols;
+               int row, col;
+               gis_tile_foreach_index(tile, row, col) {
+                       GisTile *child = tile->children[row][col];
+                       if (child && child->data) {
+                               _draw_tiles(opengl, child);
+                       } else {
+                               const gdouble n = tile->edge.n-(lat_step*(row+0));
+                               const gdouble s = tile->edge.n-(lat_step*(row+1));
+                               const gdouble e = tile->edge.w+(lon_step*(col+1));
+                               const gdouble w = tile->edge.w+(lon_step*(col+0));
+                               GList *these = roam_sphere_get_intersect(opengl->sphere, FALSE, n, s, e, w);
+                               triangles = g_list_concat(triangles, these);
+                       }
+               }
+       } else {
+               triangles = roam_sphere_get_intersect(opengl->sphere, FALSE,
+                               tile->edge.n, tile->edge.s, tile->edge.e, tile->edge.w);
+       }
+       if (triangles)
+               _draw_tile(opengl, tile, triangles);

 }
 
 static void _draw_marker(GisOpenGL *opengl, GisMarker *marker)
 }
 
 static void _draw_marker(GisOpenGL *opengl, GisMarker *marker)


@@ -270,6 +291,8 @@ static void _draw_object(GisOpenGL *opengl, GisObject *object)
        } else if (GIS_IS_CALLBACK(object)) {
                _draw_callback(opengl, GIS_CALLBACK(object));
        } else if (GIS_IS_TILE(object)) {
        } else if (GIS_IS_CALLBACK(object)) {
                _draw_callback(opengl, GIS_CALLBACK(object));
        } else if (GIS_IS_TILE(object)) {

+               glEnable(GL_DEPTH_TEST);
+               glDepthFunc(GL_LESS);

                _draw_tiles(opengl, GIS_TILE(object));
        }
        glPopAttrib();
                _draw_tiles(opengl, GIS_TILE(object));
        }
        glPopAttrib();